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Throughout this study, the SiO2, Na2O and H2O contents in the starting gel were modified in order to understand their influence on obtaining pure Y faujasite small crystals. Results were assembled in a ternary phase diagram (SiO2–H2O–Na2O). Furthermore, thorough characterization using multiple structural and physicochemical methods is reported for all the pure faujasite samples, in order to emphasize the effect of H2O, SiO2 and Na2O amounts on their structural (the crystallization rate and the Si/Al molar ratio of the framework) and textural properties (the micropore volume and the crystal size). Good yields in Y faujasite small crystals were obtained when optimizing the starting gel composition compared to the one provided in the literature (typically below 10 wt% of the engaged Si). The results show that the gel domains that are able to give pure Y zeolites are very restricted, making predictions very complicated.

The impact of crystal size and textural properties of * BEA-type zeolites in the conversion of ethanol-to-hydrocarbons at 350 °C and under 3.0 MPa pressure is investigated. Three * BEA zeolites (molar ratio Si/Al of ca. 23) with important differences concerning their textural properties are synthesized: a material constituted of micron-sized crystals and two hierarchical porous zeolites with a mesoporous network created either by the aggregation of nanometer-sized crystals or by the use of a gemini-type quaternary ammonium surfactant given a nano-sponge zeolite. The micrometric zeolite favors the formation of polyaromatic molecules in same proportion than the concentration of Bronsted acid sites. The deactivation mode of acid sites is poisoning rather than pore blocking. The short thickness of crystal in the nano-sponge zeolite combined with its low acidity, limit the growth of coke molecules as well as their accumulation inside micropores. Coke precursors (alkylbenzenes) are adsorbed on many silanol group located in the ordered mesopores, but the extreme downsizing of the zeolite crystal leads to an unexpected pore blocking by these light molecules.

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International audience; A new medium-pore germanosilicate, denoted IM-18, with a three-dimensional 8 × 8 × 10-ring channel system, has been prepared hydrothermally using 4-dimethylaminopyridine as an organic structure-directing agent (OSDA). Due to the presence of stacking disorder, the structure elucidation of IM-18 was challenging, and a combination of different techniques, including electron diffraction, high-resolution transmission electron microscopy (HRTEM), and Rietveld refinement using synchrotron powder diffraction data, was necessary to elucidate the details of the structure and to understand the nature of the disorder. Rotation electron diffraction data were used to determine the average structure of IM-18, HRTEM images to characterize the stacking disorder, and Rietveld refinement to locate the Ge in the framework and the OSDA occluded in the channels

SSCI-VIDE+ING+CPG:ATU:DFA; International audience; Highly crystalline hollow Y zeolite has been obtained by post-synthesis modification of conventional NaY crystals. The top-down transformation involves substantial dealumination of the zeolite framework by silicon tetrachloride followed by acid leaching and finally selective dissolution of the crystal core in the presence of protective aluminium species. The formation of internal cavities depends on the extent of dealumination of the zeolite as well as on the efficiency to remove extraframework Al species prior to realumination. Hollow Y zeolite crystals possess more or less regular internal cavities of ca. 0.8 μm diameter with external size and shape similar to those of the original NaY crystals. They differ from those recently reported in the literature by much higher Si/Al ratios, higher crystallinities and pure microporous shells of ca. 0.12 μm thickness. As a result of these differences, the family of hollow faujasites is significantly enlarged towards more siliceous and less defective materials. Their formation is most likely based on the presence of an Al-rich surface generated by NaAlO2 species during the last stage of the process, which protects the outer parts of the crystals from desilication.

SSCI-VIDE+ING+CPG:ATU:DFA; International audience; Hollow polycrystalline Y zeolite spheres have been obtained by combining zeolite crystallization and selective dissolution steps. Beta-Y core shell composites were first obtained by hydrothermal recrystallization of a synthesis mixture containing as-made Beta crystals in the presence of Y zeolite seeds. Under such conditions, Beta zeolite crystals served not only as cores but they also progressively dissolved and provided the necessary Si species for the formation of the shell. The proportion of Beta zeolite remaining in the composite strongly depended on the composition of the solution, in particular the amount of Al and the alkalinity. It could not be decreased below 45–50 wt. % without formation of contaminating phases, mainly zeolites with GME, GIS and LTA topologies. Successive additions of Al could significantly reduce the amount of Beta zeolite in the composite but to the detriment of faujasite crystal size. Hollow shells with less than 10 wt. % Beta have been obtained by selective removal of Beta zeolite from a composite containing 20 wt. % Beta and obtained after two successive recrystallizations in the presence of aluminum. These shells are built up from faujasite nanocrystals with a high silicon content, making them potentially interesting in diffusion-limited catalytic reactions.

We present a Pt@Beta catalyst with a unique, well-controlled location of metal nanoparticles that allows more efficient use of this rare, expensive metal in catalysis. The zeolite crystal has an inner cavity, leaving a thin zeolite shell where the metal nanoparticles are encapsulated, thereby ensuring a relatively small diffusional path length and high selectivity. Hollow Beta is obtained by a controlled dissolution–recrystallization method. The location of the particles not only was revealed by electron tomography 3D reconstruction but was further confirmed by a model hydrogenation reaction of aromatics.

International audience; Zeolites are porous materials with important industrial applications. They are synthesized and used in polycrystalline form, and have complex, sometimes disordered structures, which makes their structure characterization difficult usingconventional methods. IM-18 is a germanosilicate zeolite that was discovered more than 8 years ago, but its complexstructure has remained elusive [1]. To determine its structure, we combined rotation electron diffraction (RED) [2] with high-resolution transmission electron microscopy (HRTEM) and powder X-ray diffraction (PXRD). The RED method combines discrete goniometer tilt (2.0-3.0°/step) with fine beam tilt (0.05-0.20°/step) to collect 3D ED data from a single nano-sized crystal. Although the 3D reciprocal lattice clearly showed diffuse streaks, indicating the presence of disorder, the average structure of IM-18 could be solved using direct methods. Characterization of the disorder using HRTEM proved difficult, because germanosilicates are sensitive to radiation damage. Therefore, we have developed a method for structure projection reconstruction from a through-focus series of HRTEM images acquired with a constant step of defocus changes, implemented in the program QFocus [3]. The structure projection reconstruction method is ideal for beam sensitive materials, because it allows fast data collection without the need of manually optimizing the defocus. The contrast of the reconstructed HRTEM image is greatly improved and the image can be directly interpreted in terms of structure projection. Several through-focus series of 12 HRTEM images with a defocus step of 85.3Å were taken along the b-axis of IM-18, and the structure projections were reconstructed using QFocus (Fig. 1C). By combining this information with the RED data, we were able to understand the structure and disorder of IM-18 and to refine its structure against the synchrotron XRPD data. The crystal structure of IM-18 is monoclinic (P2/m) with a = 10.509(5) Å, b = 14.943(5) Å, c = 17.774(9) Å, β = 107.29(6)° (Fig. 1A). The average structural model obtained from the RED data indicated the presence of disorder in the sample, because the double-4 rings (d4rs) are too close to each other and cannot exist simultaneously. IM-18 contains three-dimensional intersecting channels along a-, b- and c-axis defined by 8, 10, 8 vertex-sharing (Ge, Si)O4 tetrahedra, respectively. Rietveld refinement (Fig. 1B) helped to understand the average disorder in IM-18, indicating that there are two domains related by a shift of 1/2a. Further refinement revealed the location of the organic structure directing agent (OSDA) within the channel system.

International audience; Despite having been used in hydrocracking processes for decades, zeolite Y is still nowadays the subject of intense research aiming at improving its physicochemical properties. Here, and for the first time, the synthesis of zeolite Y nanocrystals prepared in organic template-free medium, featuring both extremely reduced dimensions (mean diameter below 30 nm) and a high silicon to aluminum ratio (Si/Al ≈ 2.2), is reported. The singularity of the protocol lies in the progressive adding of a silica source during synthesis combined with the use of prolonged aging times. These high-silica ultra-nanosized zeolite Y crystals display excellent textural properties (Vmicropore = 0.33 cm3/g and SBET = 830 m2/g), comparable to their microsized counterparts. In this work, the extensive study of the influence of various parameters (i.e., gel composition, aging time, and crystallization conditions) intended for the optimization of the synthesis protocol is also presented.

Molecular modelling is a growing science which allows to calculate short range forces between zeolite frameworks and organic compounds. By using a steric approach, it is possible to design templates matching closely with an inorganic framework. Herein, the design, synthesis and successful application of several di(azacrown ether) templates to direct the formation of FAU- and EMT-type zeolites are reported. Following a high throughput experiment design, the synthesis gel composition was optimized to obtain well-crystallized materials. Taking into account their respective crystallization rates, their textural and morphological properties were comparable to their counterparts, typically structured by 15-crown-5 and 18-crown-6 ethers. This work is the first step toward a further design of structure- and shape-directing templates, in order to control the properties of FAU- and EMT-type zeolites aiming specific catalytic and separation applications.

IZM-2 (IFPEn Zeolitic Material number 2) is an aluminosilicate zeolite with unknown structure. The synthesis is performed using 1,6-bis(methylpiperidinium)hexyl dibromide template. According to SEM and TEM, IZM-2 particles consist of intergrowths of 20–60 nm nanocrystals of various orientations. The nitrogen adsorption isotherm is characteristic of a nanosize microporous material. Characterization of the pore architecture using m-xylene isomerization and disproportionation and n -decane isomerization-hydrocracking test reaction suggests the presence of two types of pores of different diameter. The catalytic fingerprints of 10-membered ring pores are observed and concluded to be present next to wider pores, tentatively qualified as 12-membered ring pores. Pt/IZM-2 was evaluated in the hydroisomerization of n -hexadecane. Pt/IZM-2 is an excellent hydroisomerization catalyst especially suited for formation of multi-branched skeletal isomers. IZM-2 is a valuable addition to the family of 10-membered ring zeolites and may find application in hydroisomerization processes for selective hydroisomerization of long-chain n -alkanes.

The influence of l -lysine, one of the most basic amino acids, and poly(diallyldimethylammonium) (PDADMA) poly(cations) with different molecular weights on the zeolite Y crystal size and porosity was evaluated by using a high-throughput experiment (HTE) approach, allowing the exploration of a wide range of organic compound concentrations under the same experimental conditions. Depending on their nature and molecular weight, the increased concentration of these organic compounds into the synthesis gel gradually delays the crystallization of the zeolite Y. An intermediate molar content of the amino acid (1 l -lysine:9 SiO 2 ) led to slight decrease of the crystallization rate and a significant reduction of the crystal size down to 300 nm. Thus, the l -lysine is assumed to act as a growth inhibitor. The addition of poly(cations) to the synthesis gel results in the creation of silica-rich mesoporous particles forming aggregates. The PDADMA is mainly located in the silica-rich particles and favor their formation along with their mesoporosity. The larger crystal size is attributed to the inhibition of the nucleation process by the poly(cations).

Hollow capsules with dimensions below 1 μm have recently attracted much attention due to their potential applications as catalysts as well as biomedical and pharmaceutical vectors for controlled drug delivery. Among them, hollow zeolites are particularly interesting because they possess (i) a crystalline structure, which greatly improves their hydrothermal and chemical stability as compared to amorphous silica analogs and (ii) a microporous network that acts as a shape-selective membrane. Moreover, their properties can be continuously tuned by changing their composition, in particular the framework aluminum content. In this perspective review, we examine the recent progress in the development of synthetic methods for the preparation of hollow zeolite and zeotype structures, from templating routes providing large polycrystalline capsules to controlled dissolution methods leading to nanometer-sized hollow single crystals. The applications of these materials will be illustrated and discussed, namely their ma...

International audience; A series of *BEA-type zeolites with crystal sizes ranging from few nanometers to micrometers were synthesized. These materials were then transformed into bifunctional catalysts by platinum loading and tested in n-hexadecane isomerization. The behavior of Pt/H-*BEA catalysts depends on several parameters such as the balance between the platinum and acid functions, the metal particle size and the zeolite crystal size. In order to design an “ideal” bifunctional catalyst, the metal and acid sites must be well balanced to avoid the cracking of isomer products at low conversion, the metal must be well dispersed in order to inhibit the hydrogenolysis side reactions, and the crystal size must be as small as possible to maximize the isomer yield. But, the extreme decrease of the zeolite crystal thickness to few zeolite unit cells lowers the turnover frequency of acid sites and favors the metal sintering.

SSCI-VIDE+ING+CPG:DFA:ATU; International audience; Hollow capsules with dimensions below 1 mu m have recently attracted much attention due to their potential applications as catalysts as well as biomedical and pharmaceutical vectors for controlled drug delivery. Among them, hollow zeolites are particularly interesting because they possess (0 a crystalline structure, which greatly improves their hydrothermal and chemical stability as compared to amorphous silica analogs and (ii) a microporous network that acts as a shape-selective membrane. Moreover, their properties can be continuously tuned by changing their composition, in particular the framework aluminum content. In this perspective review, we examine the recent progress in the development of synthetic methods for the preparation of hollow zeolite and zeotype structures, from templating routes providing large polycrystalline capsules to controlled dissolution methods leading to nanometer-sized hollow single crystals. The applications of these materials will be illustrated and discussed, namely their main potential as catalytic nanoreactors, these being materials particularly adapted for the encapsulation and the confinement of metal nanoparticles. Critical perspectives on future materials with specific properties are also addressed, particularly those with less common zeolite structures and/or compositions.

Adsorption kinetics of cyclohexane in a variety of Silicalite-1 samples were measured by gravimetric uptake experiments. The kinetic appears as dependent upon the history of the crystals. Samples stored for several months before calcination (with their micropores full of template) exhibit a kinetic drop by almost an order of magnitude. Surprisingly, physico-chemicals analysis do not show any differences between these samples (no modification of their crystallinity or morphology, and no residual carbon is detected in the pore network). The kinetic drop is therefore attributed to a modification of the crystals surface, induced by a long-time contact with the template or cyclohexane molecules. Aged and as-synthesized (non-calcined) samples were etched by an HF solution, so as to “purify” the surface of the crystals. After a few minutes of treatment, the aged samples recover their initial adsorption kinetic, confirming that the kinetic drop is induced by the partial blocking of the entrance of the pores. Moreover, some of the as-synthesized crystals also show a rise of their adsorption kinetic, showing that surface resistance can be present ab initio , depending on the synthesis conditions. In an attempt to produce an accelerated aging effect, hydrothermal treatments were performed on non-calcined crystals. However, the treatments conditions are too severe, and induce variations in the crystal structure.

A new approach was undertaken to increase the bifunctionality of USY zeolite based catalyst. Nickel metallic phase was first impregnated onto USY zeolite and composite catalysts NiMo/[γ-Al2O3 + (Ni)/USY] were prepared from these zeolites. Catalytic properties in toluene hydrogenation and squalane (2,6,10,15,19,23-hexamethyltetracosane) hydrocracking (HCK) were investigated. Enhanced conversion and middle distillate (MD) selectivity was obtained for catalysts on which nickel has been impregnated on the zeolite powder. These enhancements are ascribed to an increased proximity between the hydrogenation/dehydrogenation (H/DH) function and the acid sites resulting in a more efficient synergy between these two functions., The authors would like to acknowledge Stephane Cremer and Laetitia Assie for technical support and the IFP Energies nouvelles Physic and Analyses Division staff for their collaboration in this work. J.F. acknowledges the ANRT and IFP Energies nouvelles for Ph.D. research grant.

3 Aguado, Sonia Bergeret, Gerard Titus, Marc Pera Moizan, Virginie Nieto-Draghi, Carlos Bats, Nicolas Farrusseng, David; The zinc benzimidazolate coordination polymer (ZIF-7) shows a reversible gate-opening effect upon variation of partial pressure of CO2 or temperature. This phenomenon, which is unique for a MOF with sodalite topology, arises from a phase-to-phase transformation upon guest adsorption-desorption.

The zeolite imidazolate framework ZIF-8 is shown for the first time to be able to catalyze transesterification of vegetable oil with significant activity. Rationalization of this behavior at the atomic scale is provided by combining CO adsorption monitored by FTIR and DFT calculations (clusters and periodic models). We demonstrate that the acido-basic sites are located at the external surface of the material or at defects, but not in the microporosity of ZIF-8. A great variety of sites are found the surface: OH and NH groups, hydrogenocarbonates, low-coordinated Zn atoms, and free N(-) moieties belonging to linkers. Their proportions depend on the operating conditions (temperature and pressure). The acido-basicity of the surface is then probed by adsorption of CO at low temperature. In parallel, the species present are mapped by DFT calculations combined with a thermodynamic model. An assignment of the CO region of the FTIR spectra can thus be proposed. The complex infrared spectrum is attributed to the coexistence of classical C-adducts of CO with acid sites and other modes on basic sites (O-adducts and side-on adducts). Adsorption energies and CO frequency shifts show that some strong Lewis sites exist (in particular Zn(II) species), as well as strong Brønsted acid sites (NH groups), together with basic sites (OH groups and N(-) moieties). By calculating the co-adsorption of a model ester (methyl acetate) and methanol, we show the prevailing role of Zn(II) species as acid sites, combined with N(-) moieties and OH groups as basic ones, in determining the catalytic properties of ZIF-8. This work opens new perspectives on the use of MOFs in catalysis and, more generally, on the properties of their external surface.

Molecular modeling has been used to assist in the design of a new structure directing agent (SDA) for the synthesis of the AlPO(4) form of STA-2, bis-cliazabicyclooctane-butane (BDAB). This is incorporated as a divalent cation within the large cages of STA-2, as determined via a combination of solid-state (13)C and (15)N MAS NMR, supported by (14)N and (1)H-(15)N HMQC solution NMR and density functional calculations. As prepared AlPO4 STA-2 containing cationic SDA molecules achieves neutrality by the inclusion of hydroxide ions bridging between 5-fold coordinated framework Al atoms. Synchrotron X-ray powder diffraction data of the dehydrated as-prepared form indicates triclinic symmetry (Al(12)P(12)O(48)(OH)(2)center dot BDAB, P1, a = 12.3821(2) angstrom, b = 12.3795(2) angstrom, c = 12.3797(3) angstrom, alpha = 63.3585(8)degrees, 63.4830(7)degrees, gamma = 63.4218(7)) with the distortion from rhombohedral R (3) over bar symmetry resulting from the partial order of hydroxide ions in bridging Al-OH-Al sites within cancrinite cages. Upon calcination in oxygen, the organic SDA is removed, leaving AlPO(4) STA-2 with a pore volume of 0.22 cm(3) g(-1) (R (3) over bar, Al(36)P(36)O(144), a = 12.9270(2) angstrom, c = 30.7976(4) angstrom). Dehydrated calcined AlPO(4) STA-2 has two crystallographically distinct P and Al sites: (31)P MAS NMR resolves the two distinct P sites, and although 27AI MAS NMR only partially resolves the two Al sites, they are separated by MQMAS. Furthermore, 2D (27)Al -> (31)P MQ-J-HETCOR correlation spectroscopy confirms that each framework Al is linked to the two different P sites via AI-O-P connections in a 3:1 ratio (and vice versa for P linked to different Al). The (27)Al and (31)P resonances are assigned to the crystallographic Al and P sites by calculation of the NMR parameters using the CASTEP DFT program for an energy-minimized AlPO(4)(SAT) framework.

To study the energetic performance of the 1D 12-membred-ring pure silica ITQ-4 zeolite (IFR topology), a high-pressure water intrusion−extrusion isotherm at room temperature was performed. The pressure−volume diagram indicates an irreversible phenomenon, water molecules remaining confined in ITQ-4 micropores. Therefore, the “water−ITQ-4” system appears to behave as a bumper. The water intrusion pressure and intruded volume are of 42 MPa and 0.136 mL/g, respectively. Investigations on the ITQ-4 samples by 29Si and 1H solid-state NMR spectroscopy and powder X-ray diffraction have confirmed the existence of a small amount of silanol defects in the nonintruded sample and an increase of these defects after the water intrusion−extrusion experiment. It appears clearly that one of the crystallographic silicon sites of the porous framework is particularly affected after such a treatment, leading to the creation of Si−OH groups by the breaking of siloxane bonds, these silanols being strongly hydrogen bonded with wa...

Gravimetric uptake measurements were performed with cyclohexane for different Silicalite-1 crystals sizes. It was observed that the apparent diffusion coefficients vary with crystal size, confirming the existence of a surface resistance. Considering that surface and the intracrystalline characteristic diffusion times are additives, it was possible to dissociate the two resistances. Surface mass transfer coefficient was found to be in the same order of magnitude for the different samples and activated with temperature. The contribution of surface resistance to mass transfer limitation is lower at high temperatures and for the bigger crystals. Surface resistance is far from being negligible for the smaller crystals: for crystals of 2 μm, surface resistance represents more than 60% of the total mass transfer resistance at 398 K. And crystals of that size (in the order of 2 μm) are usually used industrially, in order to minimize mass transfer resistance. The surface of one of our sample was purified by etching with a solution of hydrogen fluoride, without any enhancement of the adsorption kinetic. Surface resistance may not be located at the extreme surface of the crystals but in a layer of non negligible thickness of distorted crystal structure around the crystals.

Ravon, Ugo Chaplais, Gerald Chizallet, Celine Seyyedi, Behnam Bonino, Francesca Bordiga, Silvia Bats, Nicolas Farrusseng, David; International audience

The external surface sites of zinc based zeolite imidazolate frameworks (ZIFs) is investigated by cluster density functional theory calculations, which reveal a great variety of sites. Their stabil...

The synthesis and the structure of IM-16 a new germanosilicate with a novel zeolitic topology prepared hydrothermally with the ionic liquid 3-ethyl-1-methyl-3H-imidazol-1-ium as the organic structure-directing agent are reported. The structure of calcined and partially rehydrated IM-16 of chemical formula |(H{sub 2}O){sub 0.16}|[Si{sub 3.47}Ge{sub 2.53}O{sub 12}] was solved from powder XRD data in space group Cmcm with a=15.0861(2) A, b=17.7719(3) A, c=19.9764(3) A, V=5355.84(12) A{sup 3} (Z=16). This new zeolite framework type contains 10-MRs channels and may be described from the d4r and mtw composite building units. - Graphical abstract: The synthesis and the structure of IM-16 a new germanosilicate with a novel zeolitic topology prepared hydrothermally with the ionic liquid 3-ethyl-1-methyl-3H-imidazol-1-ium as the organic structure-directing agent are reported. This new zeolite framework type contains 10-MRs channels and may be described from the d4r and mtw composite building units.

This paper deals with the synthesis results obtained mostly from pure silica systems in the presence of (CH3 )3 N+ (CH2 )n N+ (CH3 )3 ions (n = 5 , 6, 9 or 10) in fluoride media, but also in the presence of (CH3 )3 N+ (CH2 )n O(CH2 )n N+ (CH3 )3 ions (n = 2 or 4) in hydroxide or fluoride media. A variety of zeolites form, namely ZSM-48, MTW-type, BEA-type, MFI-type, ITH-type zeolites, but also, in case of pronounced degradation of the template into N(CH3 )4 + or N(CH3 )3 , AST-type, MTN-type and RUT-type materials. The samples are characterized by XRD, SEM, thermal and elementary analyses, 1 H liquid NMR (after dissolution of the sample in HF aqueous solution) and solid-state NMR (19 F, 13 C, 27 Al) spectroscopy.

International audience; NEXTLAB 2014-Advances in Innovative Experimental Methodology or Simulation Tools used to Create, Test, Control and Analyse Systems, Materials and Molecules NEXTLAB 2014-Innover dans le domaine de la méthodologie expérimentale et des outils de simulation pour créer, tester, contrôler et analyser des systèmes, matériaux et molécules Abstract — By using a steric approach, it is possible to design templates matching closely with an inorganic framework. Herein, the design, synthesis and successful application of several di(azacrown ether) templates to direct the formation of EMC-1 zeolite (FAU-type) are reported. Following a high throughput experiment design, the synthesis gel composition was optimized to obtain well-crystallized materials. Taking into account their respective crystallization rates, their textural and morphological properties were comparable to their counterparts, typically structured by 15-crown-5 ether. Re´umeútilisation d'agents structuraux originaux pour lasynthè se de zeólithe EMC-1 — En utilisant une approche « ste´ique », il est possible de concevoir des agents structurants qui s'adaptent bien a` la porosite´e la charpente mine´ale. Ici, la conception, lasynthè se et l'application reússie de plusieurs agents structurants de type di(aza-e´her-couronne) pour diriger la formation de zeólithe EMC-1 de type FAU sont reporte´uite a` des synthè ses a` haut-de´it , la composition du gel desynthè se a e´eóptimiseé pour obtenir des mate´iaux bien cristallise´ompte tenu de leurs taux de cristallisation respectifs, leurs proprie´e´exturales et morphologiques sont comparables a` leurs homologues, ge´e´alement synthe´iseén pre´ence du 15-e´her-couronne-5.

A novel GeO2 or (Si,Ge)O2 zeolite phase called IM-10 was obtained in the presence of the well-known hexamethonium ion as template and in fluoride media, from gels with Ge/Si molar ratios ⩾1. With decrease of the Ge/Si molar ratio, BEC-type zeolite and ITH-type zeolite were successively obtained. The recovered IM-10 samples were characterized by X-ray diffraction, SEM, elemental and thermal analysis, 19F MAS and 1H liquid (after dissolution of the samples in HF) spectroscopies. Due to the small crystal sizes (1–4 μm), the structure was determined from powder X-ray diffraction (of the GeO2 as-made sample) and refined by the Rietveld method. IM-10 is a new member of the clathrate family. It crystallizes in the tetragonal symmetry, the space group being P 4 ¯ n 2 . The framework is made of F−-containing D4R units, bridged by GeO4 tetrahedra. The arrangement of the D4R units creates [62042] supercages, each of them occluding one hexamethonium cation. Structural similarities exist between ASU-9 (AST), ASU-7 (ASV) and the new IM-10 zeolite with a novel topology (UOZ).

International audience; The synthesis of an original compound consisting of an azacrown ether interconnected with a diazacrown ether bearing an alkyl chain is described herein. This derivative is promising for numerous applications.

International audience; A commercial copper exchanged zeolite was characterised and studied regarding the selective catalytic reduction of nitrogen oxides (NOX) by ammonia using physicochemical analyses (XRF, XRD, NMR, BET, UV-Visible, IR) and synthetic gas bench test rig, respectively. As expected, two adsorption sites were identified for ammonia: Bronsted and Lewis acid sites, the latter retaining stronger ammonia. Furthermore, ammonia and water adsorb on the same sites, and competition phenomena decrease ammonia storage capacity. Concerning the NOX conversion, in spite of a high efficiency, an important selectivity into N2O is noticed, due to the formation of an ammonium nitrate by-product on the catalyst surface. The limited NOX conversion efficiency at low temperature is due to the weak NO oxidation activity, whereas NH3 oxidation activity at high temperature involves a decrease in NOx reduction.

INGENIERIE+JEC:DFA; We serendipitously found that a functionalized MOF containing grafted copper species can react with itself without solvent in order to modify the chemical functions present on its walls. The use of EPR techniques allows new insight into the copper-mediated azide reduction.

1 Aguado, Sonia Nicolas, Charles-Henri Moizan-Basle, Virginie Nieto, Carlos Amrouche, Hedi Bats, Nicolas Audebrand, Nathalie Farrusseng, David; A substituted imidazolate-based MOF (SIM-1) membrane has been crystallized in situ on a tubular asymmetric alumina support that can be exploited for gas separation through preferential adsorption.

A key to address advanced MOF materials suitable for more sophisticated applications is to add functionalities of greater complexity in a controlled manner. We report a generic and original post-synthetic modification method starting from amino derived MOFs. The first step consists in converting the amino group into azide (N3). Without isolation nor purification, the desired functionalized material is obtained by grafting the corresponding alkyne using “Click Chemistry”. This work reports for the first time the synthesis of a two-dimensional combinatorial library of 24 functionalized MOFs. We also show that the grafting yield can be controlled from 10 to 100%. Finally, we compare the effect of the grafting yield on the porous volume of (1D) and (3D)MOF porous structures.

IM-20 is a novel microporous germanosilicate with an interesting zeolitic structure. It has been prepared via the fluoride route with 3-butyl-1-methyl-3H-imidazol-1-ium as the organic structure-directing agent and its structure solved from synchrotron powder X-ray diffraction data. The chemical formula per unit cell is Si(42.2)Ge(17.8)O(120) under its calcined form. IM-20 possesses a new framework topology, the 3D channel system being formed by straight intersecting 12- and 10-membered rings. Two types of d4r composite building units are present in IM-20, their average Si/Ge molar ratio being about 8.52 or 0.56. Surprisingly, the pure silica or silica-rich units are fluoride-free in the as-synthesized material.

Savonnet, Marie Bazer-Bachi, Delphine Bats, Nicolas Perez-Pellitero, Javier Jeanneau, Erwann Lecocq, Vincent Pinel, Catherine Farrusseng, David; This study deals with the development of a soft, generic, one-pot postfunctionalization method for metal-organic frameworks (MOFs) starting from compounds with an amino group on the linker. The first step consists of transforming the amino group into azide (N-3) by an unconventional route using tBuONO and TMSN3. In the same vessel, the desired functionalized MOF then is obtained by the Huisgen 1,3-dipolar cycloaddition of azides to alkynes, otherwise known as the "click" reaction. The method was applied to DMOF-NH2 and MIL-68(In)-NH2, which represent two distinct and important classes of MOF. For both, the functionalization was complete (>90% grafting) and the crystallinity was maintained. Thanks to the large diversity and availability of cyano- and acetylene-based chemicals, this method opens the door to tailor-made functionalized MOFs.

International audience; Experimental measurements and molecular simulations were conducted for two zeolitic imidazolate frameworks, ZIF‐8 and ZIF‐76. The transferability of the force field was tested by comparing molecular simulation results of gas adsorption with experimental data available in the literature for other ZIF materials (ZIF‐69). Owing to the good agreement observed between simulation and experimental data, the simulation results can be used to identify preferential adsorption sites, which are located close to the organic linkers. Topological mapping of the potential‐energy surfaces makes it possible to relate the preferential adsorption sites, Henry constant, and isosteric heats of adsorption at zero coverage to the nature of the host–guest interactions and the chemical nature of the organic linker. The role played by the topology of the solid and the organic linkers, instead of the metal sites, upon gas adsorption on zeolite‐like metal–organic frameworks is discussed.

Savonnet, Marie Aguado, Sonia Ravon, Ugo Bazer-Bachi, Delphine Lecocq, Vincent Bats, Nicolas Pinel, Catherine Farrusseng, David; Metal-Organic Frameworks (post-)functionalised with nitrogen containing moieties undergo solvent free aza-Michael condensation and transesterification, surpassing molecular and functionalised MCM-type analogues.

Hydrothermal synthesis with hexamethylenediamine and ethylenediamine as structure directing agents and amorphous GeO 2 and SiO 2 as framework atoms sources in hydroxide or fluoride media led to IM-13, IM-14 and IM-15, three new materials. The structures of IM-14 and IM-13 were investigated using direct methods on powder X-ray diffraction data and the charge flipping method on a single crystal, respectively. Both materials are open framework structures displaying common structure building units.

Hydrothermal synthesis with ethylenediamine as structure-directing agent and amorphous GeO2 as framework atom source led to IM-14, a new open-framework material of formula |(enH2)2 (H2O)2.3|[Ge8O17(OH)2] of which the 3D-framework holds intersecting channels delimited by 8- and two distinct 10-membered rings. The structure of IM-14 was investigated using powder X-ray diffraction data: monoclinic, space group P21/a, a = 20.2023(13) A, b = 14.9647(8) A, c = 7.7017(4) A, β = 91.076(4)°, V = 2328.0(3) A3 and Z = 4. This material was also characterised by chemical and thermal analyses, SEM, 1H–13C MAS DEC NMR spectroscopy, 1H and 13C liquid NMR spectroscopies after dissolution in HF.

A ‘co-templating’ strategy supported by molecular modelling has been used to prepare, for the first time, silicoaluminophosphates with the SAV and KFI framework topologies, each of which has a three-dimensionally connected pore system with high specific volume.

This paper deals with the synthesis results obtained from pure silica and (Si, Ge) systems in presence of hexamethonium cations, Kryptofix2,2,2 and 5-azoniaspiro[ [4] , [5] ]decane derivative cations as organic structure directing agents (OSDA) in hydroxide or fluoride media. The obtained new materials Mu-31, IM-9, IM-10 (UOZ), IM-11(LTA), IM-12 (UTL) all contain D4MR units, confirming the orienting effect of the germanium and/or the fluoride anions towards this small cage. Surprisingly, the extra-large pore IM-12 zeolite could not be obtained in the fluoride medium.

Stable zeolites that have larger pore apertures and a three-dimensional pore topology are of interest because they could be used to adsorb larger molecules, particularly for application in oil refining. Several large-pore zeolitic materials with channels formed by openings of more than 12 rings are known, but all of them have a one-dimensional channel system that limits their use in catalysis. We report the synthesis and some characterizations of IM-12, a thermally stable germanium-containing zeolite that contains the first two-dimensional channel system with extra-large pores formed by 14- and 12-ring channels.

Hexamethonium salts are well known as structure directing agents in zeolite synthesis. Usually, hexamethonium bromide is used in alkaline medium to give zeolite EU-1 (EUO structure-type) or ZSM-48 (no structure-type). A new method of synthesis which consists in using organic precursors of the hexamethonium cation for the preparation of EU-1 zeolite will be described. The present paper also reports the use of hexamethonium dihydroxide in fluoride media which allowed the formation of a ZSM-48 type-material and of 2 new zeolites. The structure of the latter display D4R (double four-membered-ring) cages with F− ions occluded inside. IM-7 zeolite is identical to ITQ-13 zeolite recently published by Corma et al [9], whereas the silicogermanate or germanate IM-10 zeolite corresponds to a new topology.

International audience; The synthesis and the structure of IM-17, a new germanosilicate with a novel zeolitic topology, prepared hydrothermally with decamethonium as the organic structure directing agent, are reported. The structure of calcined and partially rehydrated IM-17 of chemical formula per unit cell |(H2O)14.4|[Si136.50Ge39.50O352] was solved ab initio using electron diffraction ADT data in the acentric Amm2 (setting Cm2m) space group and refined by the Rietveld method. This new zeolite framework type contains a 3D pore system made of intersecting 12, 10 and 8-ring channels.